Alert archive / Puerto Rico / Flash Flood Warnings in 2020

Flash Flood Warning 7, NWS JSJ

July 30, 2020

NWS JSJ issued this flash flood warning at Jul 30, 2020, 4:18 AM CDT. It was in force for 11 hr. 4 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Jul 30, 2020, 4:18 AM CDT (09:18 UTC)
Expired: Jul 30, 2020, 3:15 PM CDT
In force: 11 hr
Issued by: NWS JSJ
Area: Storm-based polygon
Flood severity: None

The radar

The San Juan radar (TJUA), 18 km from the middle of the area, began a volume at 09:21 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What was reported inside it

Time	Report	Where	Remark
Jul 30, 9:00 AM CDT	FLASH FLOOD	Caguas, PR	FLOODING REPORTED IN CALLE LUIZ MUNOZ MARIN WITH THE INTERSECTION OF CALLE ZAFIRO.
Jul 30, 9:00 AM CDT	FLASH FLOOD	Gurabo, PR	ROADS PR-941, PR-943 AND PR-181 WERE CLOSED DUE TO SIGNIFICANT FLOODING AS RIO GURABO WENT OUT OF ITS BANKS.
Jul 30, 9:30 AM CDT	FLASH FLOOD	Caguas, PR	CAGUAS OMME EMERGENCY MANAGER REPORTED ROAD ALONG RAFAEL CORDERO AVE,NEAR CAGUAS NROTE IMPASSABLE DUE TO CONSIDERABLE FLOODING.
Jul 30, 9:30 AM CDT	FLASH FLOOD	Caguas, PR	EMERGENCY MANAGER FROM OMME CAGUAS REPORTED A MUDSLIDE IN RD 172 NEAR RAFI TRANSMITORS DUE TO HEAVY RAINS AND ONGOING FLASH FLOODING.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The text

As transmitted.

046 
WGCA52 TJSJ 300918
FFWSJU
PRC025-063-069-077-085-129-151-301215-
/O.NEW.TJSJ.FF.W.0007.200730T0918Z-200730T1215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service San Juan PR
518 AM AST Thu Jul 30 2020

The National Weather Service in San Juan has issued a

* Flash Flood Warning for...
  Humacao Municipality in Puerto Rico...
  Gurabo Municipality in Puerto Rico...
  Yabucoa Municipality in Puerto Rico...
  Caguas Municipality in Puerto Rico...
  Juncos Municipality in Puerto Rico...
  Las Piedras Municipality in Puerto Rico...
  San Lorenzo Municipality in Puerto Rico...

* Until 815 AM AST

* At 517 AM AST, Doppler radar indicated thunderstorms producing
  heavy rain across the warned area. Up to two inches of rain have
  already fallen. Flash flooding is ongoing or expected to begin
  shortly.

  HAZARD...Flash flooding caused by thunderstorms. 

  SOURCE...Radar indicated. 

  IMPACT...Flooding of small creeks and streams, urban areas, 
           highways, streets and underpasses as well as other 
           drainage and low lying areas. 

Additional rainfall amounts of 1 to 2 inches is expected across the 
area during the next couple of hours. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.

A Flash Flood Warning means that flooding is imminent or occurring.
If you are in the warned area move to higher ground immediately.
Residents living along streams and creeks should take immediate
precautions to protect life and property.

&&

LAT...LON 1825 6588 1827 6583 1820 6583 1820 6577
      1818 6576 1817 6574 1815 6577 1806 6580
      1805 6584 1801 6583 1807 6601 1810 6601
      1812 6606 1815 6607 1817 6610 1821 6612
      1823 6609 1830 6606 1831 6597

FLASH FLOOD...RADAR INDICATED

$$

GL

3 follow-up statements

626 
WGCA52 TJSJ 301203
FFWSJU
PRC025-063-069-077-085-129-151-301515-
/O.EXT.TJSJ.FF.W.0007.000000T0000Z-200730T1515Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service San Juan PR
803 AM AST Thu Jul 30 2020

The National Weather Service in San Juan has extended the

* Flash Flood Warning for...
  Humacao Municipality in Puerto Rico...
  Gurabo Municipality in Puerto Rico...
  Yabucoa Municipality in Puerto Rico...
  Caguas Municipality in Puerto Rico...
  Juncos Municipality in Puerto Rico...
  Las Piedras Municipality in Puerto Rico...
  San Lorenzo Municipality in Puerto Rico...

* Until 1115 AM AST

* At 801 AM AST, Doppler radar indicated Isaias' rain bands 
  producing heavy rain across the warned area. Between 3 and 6 
  inches of rain have fallen. Flash flooding is already occurring.

  HAZARD...Life threatening flash flooding. Heavy rain producing 
           flash flooding. 

  SOURCE...Radar indicated. 

  IMPACT...Life threatening flash flooding of creeks and streams, 
           urban areas, highways, streets and underpasses. The Flash 
           Flooding is capable of producing unusual severity. Action 
           is needed to protect live and property. 

Additional rainfall amounts of 1 and 2 inches are possible in the 
warned area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.

A Flash Flood Warning means that flooding is imminent or occurring.
If you are in the warned area move to higher ground immediately.
Residents living along streams and creeks should take immediate
precautions to protect life and property.

&&

LAT...LON 1825 6588 1827 6583 1820 6583 1820 6577
      1818 6576 1817 6574 1815 6577 1806 6580
      1805 6584 1801 6583 1807 6601 1810 6601
      1812 6606 1815 6607 1817 6610 1821 6612
      1823 6609 1830 6606 1831 6597

FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
EXPECTED RAINFALL...1-2 INCHES IN 1 HOUR

$$

CAM

716 
WGCA52 TJSJ 301459
FFWSJU
PRC025-063-069-077-085-129-151-301815-
/O.EXT.TJSJ.FF.W.0007.000000T0000Z-200730T1815Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service San Juan PR
1059 AM AST Thu Jul 30 2020

The National Weather Service in San Juan has extended the

* Flash Flood Warning for...
  Humacao Municipality in Puerto Rico...
  Gurabo Municipality in Puerto Rico...
  Yabucoa Municipality in Puerto Rico...
  Caguas Municipality in Puerto Rico...
  Juncos Municipality in Puerto Rico...
  Las Piedras Municipality in Puerto Rico...
  San Lorenzo Municipality in Puerto Rico...

* Until 215 PM AST

* At 1054 AM AST, Doppler radar indicated another round of 
  thunderstorms producing heavy rain across the warned area. Between 
  four and eight inches of rain have fallen. Emergency managers 
  reported multiples fallen trees, mudslides and flooding across the 
  warned area. Please heed caution across rivers and tributaries. 
  Flash flooding is already occurring or will begin shortly.

  HAZARD...Life threatening flash flooding. Heavy rain producing 
           flash flooding. 

  SOURCE...Radar indicated. 

  IMPACT...Life threatening flash flooding of creeks and streams, 
           urban areas, highways, streets and underpasses. The Flash 
           Flooding is capable of producing unusual severity. Action 
           is needed to protect live and property. 

Additional rainfall amounts between one and three are possible in 
the warned area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.

A Flash Flood Warning means that flooding is imminent or occurring.
If you are in the warned area move to higher ground immediately.
Residents living along streams and creeks should take immediate
precautions to protect life and property.

&&

LAT...LON 1825 6588 1827 6583 1820 6583 1820 6577
      1818 6576 1817 6574 1815 6577 1806 6580
      1805 6584 1801 6583 1807 6601 1810 6601
      1812 6606 1815 6607 1817 6610 1821 6612
      1823 6609 1830 6606 1831 6597

FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
EXPECTED RAINFALL...1-3 INCHES IN 3 HOUR

$$

CAM

448 
WGCA52 TJSJ 301754
FFWSJU
PRC025-063-069-077-085-129-151-302015-
/O.EXT.TJSJ.FF.W.0007.000000T0000Z-200730T2015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service San Juan PR
154 PM AST Thu Jul 30 2020

The National Weather Service in San Juan has extended the

* Flash Flood Warning for...
  Humacao Municipality in Puerto Rico...
  Gurabo Municipality in Puerto Rico...
  Yabucoa Municipality in Puerto Rico...
  Caguas Municipality in Puerto Rico...
  Juncos Municipality in Puerto Rico...
  Las Piedras Municipality in Puerto Rico...
  San Lorenzo Municipality in Puerto Rico...

* Until 415 PM AST

* At 152 PM AST, Doppler radar indicated heavy rain falling across 
  the warned area. Between three and eight inches of rain have 
  already fallen, and additional rainfall amounts are expected. 
  Flash flooding is already occurring.

  HAZARD...Flash flooding caused by heavy rain. 

  SOURCE...Radar indicated. 

  IMPACT...Flooding of small creeks and streams, urban areas, 
           highways, streets and underpasses as well as other 
           drainage and low lying areas. 

Excessive rainfall over the warned area will cause mud slides near
steep terrain. The mud slide can consist of rock, mud, vegetation and
other loose materials.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.

A Flash Flood Warning means that flooding is imminent or occurring.
If you are in the warned area move to higher ground immediately.
Residents living along streams and creeks should take immediate
precautions to protect life and property.

&&

LAT...LON 1825 6588 1827 6583 1820 6583 1820 6577
      1818 6576 1817 6574 1815 6577 1806 6580
      1805 6584 1801 6583 1807 6601 1810 6601
      1812 6606 1815 6607 1817 6610 1821 6612
      1823 6609 1830 6606 1831 6597

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL...1-2 INCHES IN 2 HOUR

$$

CAM

The office that day

Everything else NWS JSJ issued on the same UTC day.

Issued	Product	Office	Lasted
Jul 30, 1:23 AM CDT	Special Marine Warning	JSJ	52 min
Jul 30, 1:39 AM CDT	Severe Thunderstorm Warning	JSJ	51 min
Jul 30, 2:29 AM CDT	Severe Thunderstorm Warning	JSJ	91 min
Jul 30, 2:39 AM CDT	Special Marine Warning	JSJ	21 min
Jul 30, 2:47 AM CDT	Severe Thunderstorm Warning	JSJ	73 min
Jul 30, 2:55 AM CDT	Special Marine Warning	JSJ	65 min
Jul 30, 4:04 AM CDT	Special Marine Warning	JSJ	86 min
Jul 30, 4:41 AM CDT	Flash Flood Warning	JSJ	7 hr
Jul 30, 4:46 AM CDT	Flash Flood Warning	JSJ	3 hr
Jul 30, 5:37 AM CDT	Special Marine Warning	JSJ	113 min
Jul 30, 5:57 AM CDT	Flash Flood Warning	JSJ	3 hr
Jul 30, 6:19 AM CDT	Flash Flood Warning	JSJ	6 hr
Jul 30, 7:22 AM CDT	Flash Flood Warning	JSJ	8 hr
Jul 30, 7:41 AM CDT	Flash Flood Warning	JSJ	3 hr
Jul 30, 8:47 AM CDT	Flash Flood Warning Considerable damage threat	JSJ	6 hr
Jul 30, 8:57 AM CDT	Flash Flood Warning	JSJ	3 hr
Jul 30, 10:40 AM CDT	Flash Flood Warning Considerable damage threat	JSJ	3 hr
Jul 30, 11:35 AM CDT	Flash Flood Warning	JSJ	3 hr
Jul 30, 11:43 AM CDT	Flash Flood Warning Considerable damage threat	JSJ	3 hr
Jul 30, 1:19 PM CDT	Flash Flood Warning	JSJ	3 hr
Jul 30, 1:40 PM CDT	Areal Flood Warning	JSJ	6 hr
Jul 30, 2:01 PM CDT	Flash Flood Warning	JSJ	89 min
Jul 30, 2:17 PM CDT	Special Marine Warning	JSJ	88 min
Jul 30, 2:24 PM CDT	Areal Flood Warning	JSJ	6 hr
Jul 30, 2:30 PM CDT	Areal Flood Warning	JSJ	6 hr
Jul 30, 2:44 PM CDT	Areal Flood Warning	JSJ	6 hr
Jul 30, 2:59 PM CDT	Small Craft Advisory	JSJ	28 hr
Jul 30, 3:02 PM CDT	Flash Flood Warning	JSJ	3 hr
Jul 30, 3:17 PM CDT	Flash Flood Warning Considerable damage threat	JSJ	118 min
Jul 30, 3:46 PM CDT	Special Marine Warning	JSJ	119 min
Jul 30, 3:52 PM CDT	Flash Flood Warning	JSJ	83 min
Jul 30, 4:15 PM CDT	Flash Flood Warning	JSJ	4 hr
Jul 30, 4:52 PM CDT	Areal Flood Warning	JSJ	6 hr
Jul 30, 5:15 PM CDT	Flash Flood Warning Considerable damage threat	JSJ	60 min
Jul 30, 5:28 PM CDT	Flash Flood Warning	JSJ	92 min
Jul 30, 6:16 PM CDT	Flash Flood Warning	JSJ	119 min
Jul 30, 6:52 PM CDT	Special Marine Warning	JSJ	53 min

Nearby

Flash Flood Warnings in Puerto Rico, 2020 Every flash flood warning in 2020

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; radar from the NEXRAD Level II archive.